Answer:
A chemical equation is balanced when the number of each kind of atom is the same on both sides of the reaction.
Explanation:
The law of conservation of matter (except in nuclear reactions) indicates that atoms can neither be created or destroyed.
The number of atoms that are in the reactants must be the same as the number of the atoms that are in the product.
The number and types of molecules can (and will) change. The atoms that make up the molecules are rearranged but the number and kinds of atoms stay the same.
Answer:

Explanation:
Hello,
In this case, for computing the atom percent, one must obtain the number of atoms of silver, gold and copper as shown below:

Thus, the atom percent turns out:

Best regards.
Change the places of 'acts against the motion of an object' and 'causes an object to change speed or direction'